98 GTX Limited 951 another idle problem.

[bohnsorge]

Hi Guys,

first of all I would like to say hello to everyone and thank you for any kind of help (and sorry for my bad English).

Moving on, I have a Sea-Doo GTX Limited 951 (on carburetors) `98 and I have a engine idle problem (I looked at threads in this forum, but did't find a match for my problem). Please take a look at the video, I think it will illustrate the problem better than I will describe.

Previously, these symptoms were at higher rpm (but engine doesn't go out). It turned out, that I had a damaged carbon ring on the shaft and damaged bellow in the water pressure regulator (water got into the hull).



The repair consisted of replacing the ring and repairing the regulator (bellow change), I also cleaned the exhaust valves, decided to replace the spark plugs with new ones and check the compression, which I think is ok, 125psi on both cylinders. After these treatments, I took my PWC for tests. It starts without any problems (both on a cold and hot engine), after the first 15 minutes of sailing, everything worked properly, so I continued my test (both slowly and at wot) for a total of 40 minutes. After those 40 minutes there was a problem like in the movie. Although this idle problem, my GTX accelerates correctly, and when I hold the throttle gently and hold 1500 rpm, nothing is happening either, the engine does not wave or go out.

Do you have any idea what might be wrong and what should I check / fix? I will be grateful for any hints / suggestions.

Regards
Borys

 

[POPPS]

7 put 10 times,,,these issues and symptoms are carb related..start simple Load test the battery and remove it from your equation Replace the plugs,,'check that the motor it is charging,,,at the battery,,check that your rav valves are working properly,,,not melted or stuck...

 

[bohnsorge]

TU @POPPS for the hints.

1. Battery is brand new.
2. Spark Plugs new (40 min of sailing).
3. I'll check charging next Saturday.
4. Rev values are clean (40 min of sailing after cleaning) and they seem to be working, but a bit worn out, I'll be replacing them in the winter.

Regards
Borys

 

[POPPS]

No need to replace rav valves,,,you clean them,,,replace any "O" rings,,,if a valve got chewed by a ring,,,then you "may" want to replace it/them,,,but that is not your scenario.

 

[bohnsorge]

OK, today's testing is complete, I have found that:

1) the idle rpm just after starting the engine in water were a bit too low - 1250-1300RPM
2) I get 12v low for 5 sec after engine started.
3) last season I had a problem with the "silent" buzzer

Ad.1 I tweaked a little idle speed, to reach a value of about 1500rpm, it solved the problem in 95%, so rest 5% i think is related to carburettors

Ad.2 I measured the voltage before starting the engine - 11.8V, so I think I have a problem with charging, because the voltage measured on battery at 3000rpm was 13.5-13.8V, at 4500rpm it reached 14.01V. Isn't it too low? I have to look for 12v low topics and read how to diagnose it.

Ad.3 At the beginning of this season, I replaced it with a new one and sometimes you don't hear it anyway, I have no idea why.

 

[POPPS]

At startup, you should have at least 12.5 v,,.if not,,,either the battery is weak,(won't take a charge),,the rectifier is weak,,,or the stator is not putting out.

 

[etemplet]

Sounds like your charging system is great but maybe a battery issue.